content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.interop.internal.operators;
  
  import java.util.NoSuchElementException;
  
  import org.reactivestreams.*;
  
  import hu.akarnokd.reactivestreams.extensions.RelaxedSubscriber;
  import io.reactivex.common.Disposable;
  import io.reactivex.flowable.internal.subscriptions.SubscriptionHelper;
  import io.reactivex.observable.*;
  
  /**
   * Consumes the source Publisher and emits its last item or the defaultItem
   * if empty.
   * 
   * @param <T> the value type
   */
  public final class FlowableLastSingle<T> extends Single<T> {
  
      final Publisher<T> source;
  
      final T defaultItem;
  
      public FlowableLastSingle(Publisher<T> source, T defaultItem) {
          this.source = source;
          this.defaultItem = defaultItem;
      }
  
      // TODO fuse back to Flowable
  
      @Override
      protected void subscribeActual(SingleObserver<? super T> observer) {
          source.subscribe(new LastSubscriber<T>(observer, defaultItem));
      }
  
      static final class LastSubscriber<T> implements RelaxedSubscriber<T>, Disposable {
  
          final SingleObserver<? super T> actual;
  
          final T defaultItem;
  
          Subscription s;
  
          T item;
  
          LastSubscriber(SingleObserver<? super T> actual, T defaultItem) {
              this.actual = actual;
              this.defaultItem = defaultItem;
          }
  
          @Override
          public void dispose() {
              s.cancel();
              s = SubscriptionHelper.CANCELLED;
          }
  
          @Override
          public boolean isDisposed() {
              return s == SubscriptionHelper.CANCELLED;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.s, s)) {
                  this.s = s;
  
                  actual.onSubscribe(this);
  
                  s.request(Long.MAX_VALUE);
              }
          }
  
          @Override
          public void onNext(T t) {
              item = t;
          }
  
          @Override
          public void onError(Throwable t) {
              s = SubscriptionHelper.CANCELLED;
              item = null;
              actual.onError(t);
          }
  
          @Override
          public void onComplete() {
              s = SubscriptionHelper.CANCELLED;
              T v = item;
              if (v != null) {
                  item = null;
                  actual.onSuccess(v);
              } else {
                  v = defaultItem;
  
                  if (v != null) {
                      actual.onSuccess(v);
                  } else {
                      actual.onError(new NoSuchElementException());
                  }
              }
          }
      }
  }
  